Fix overlay scroll bar color on elements with dark background

third_party/WebKit/Source/core/frame/FrameView.cpp

 /*
  * Copyright (C) 1998, 1999 Torben Weis <weis@kde.org>
  *                     1999 Lars Knoll <knoll@kde.org>
  *                     1999 Antti Koivisto <koivisto@kde.org>
  *                     2000 Dirk Mueller <mueller@kde.org>
  * Copyright (C) 2004, 2005, 2006, 2007, 2008 Apple Inc. All rights reserved.
  *           (C) 2006 Graham Dennis (graham.dennis@gmail.com)
  *           (C) 2006 Alexey Proskuryakov (ap@nypop.com)
  * Copyright (C) 2009 Google Inc. All rights reserved.
  *
@@ skipping 343 matching lines @@
             toFrameView(widget)->invalidateAllCustomScrollbarsOnActiveChanged();
         else if (usesWindowInactiveSelector && widget->isScrollbar() && toScrollbar(widget)->isCustomScrollbar())
             toScrollbar(widget)->styleChanged();
         if (widget->isScrollbar())
             toScrollbar(widget)->windowActiveChangedForSnowLeopardOnly();
     }
     if (usesWindowInactiveSelector)
         recalculateCustomScrollbarStyle();
 }
 
-void FrameView::recalculateScrollbarOverlayStyle()
-{
-    ScrollbarOverlayStyle oldOverlayStyle = scrollbarOverlayStyle();
-    ScrollbarOverlayStyle overlayStyle = ScrollbarOverlayStyleDefault;
-
-    Color backgroundColor = documentBackgroundColor();
-    // Reduce the background color from RGB to a lightness value
-    // and determine which scrollbar style to use based on a lightness
-    // heuristic.
-    double hue, saturation, lightness;
-    backgroundColor.getHSL(hue, saturation, lightness);
-    if (lightness <= .5)
-        overlayStyle = ScrollbarOverlayStyleLight;
-
-    if (oldOverlayStyle != overlayStyle)
-        setScrollbarOverlayStyle(overlayStyle);
-}
-
 void FrameView::clear()
 {
     reset();
     setScrollbarsSuppressed(true);
 }
 
 bool FrameView::didFirstLayout() const
 {
     return !m_firstLayout;
 }
@@ skipping 1522 matching lines @@
 void FrameView::setBaseBackgroundColor(const Color& backgroundColor)
 {
     m_baseBackgroundColor = backgroundColor;
 
     if (layoutView() && layoutView()->layer()->hasCompositedLayerMapping()) {
         CompositedLayerMapping* compositedLayerMapping = layoutView()->layer()->compositedLayerMapping();
         compositedLayerMapping->updateContentsOpaque();
         if (compositedLayerMapping->mainGraphicsLayer())
             compositedLayerMapping->mainGraphicsLayer()->setNeedsDisplay();
     }
-    recalculateScrollbarOverlayStyle();
+    recalculateScrollbarOverlayStyle(documentBackgroundColor());
 }
 
 void FrameView::updateBackgroundRecursively(const Color& backgroundColor, bool transparent)
 {
     forAllNonThrottledFrameViews([backgroundColor, transparent](FrameView& frameView) {
         frameView.setTransparent(transparent);
         frameView.setBaseBackgroundColor(backgroundColor);
     });
 }
 
@@ skipping 2192 matching lines @@
     return m_hiddenForThrottling && m_crossOriginForThrottling;
 }
 
 LayoutBox& FrameView::boxForScrollControlPaintInvalidation() const
 {
     ASSERT(layoutView());
     return *layoutView();
 }
 
 } // namespace blink